The research reported here aims to investigate the pro-environmental behavior of respondents in the context of the concept of homo socio-oeconomicus. The main research question addressed in this paper considers the pro-environmental behavior of Generation Z representatives, due to the fact that this age group is believed to display different behavior patterns. In order to identify the differences in the pro-environmental behaviors of Generation Z, the results obtained from this group have been confronted with declarations of respondents from an older group (aged 25 to 65). It is worth noting that in the research on pro-environmental behavior of households in Poland conducted so far, Generation Z has not been taken into consideration as a separate demographic, so this study aims to make a contribution to the existing research gap. The data on the surveyed population were obtained through a standardized research questionnaire. The survey was carried out using the internet surveying technique—computer-assisted web interview (CAWI). This paper uses descriptive, tabular and graphic methods to analyze and present the collected materials. The basic measures of descriptive statistics were used in the analysis of the dataset, i.e., mean, median, mode, Pearson chi-square test and Mann−Whitney U test. The conducted research has shown that the representatives of Generation Z are less engaged in pro-environmental behavior than people from the older age group. Their pro-environmental actions mainly included turning off lights when leaving a room and choosing public transportation as the basic means of transport. For the whole surveyed sample, the most highly rated pro-environmental behaviors included those imposed by legal regulations and those whose implementation brings financial benefits in the form of lower maintenance costs. The main motivating and demotivating factors determining pro-environmental behavior were predominantly economic in nature.